Butterfly valves

ABSTRACT

A butterfly valve for handling materials where the temperature of the materials flowing through the butterfly valve can exceed the breakdown temperature of the sealing member with the butterfly valve inhibiting contact of hot transportable materials with the sealing member to isolate the hot transportable materials from the sealing member. Cooling conduits maintain at least portions of the valve that contacts the sealing member at a temperature below the breakdown temperature of the sealing member to prevent seal failure.

FIELD OF THE INVENTION

This invention relates generally to butterfly valves and, morespecifically, to butterfly valves for use with hot materials.

CROSS REFERENCE TO RELATED APPLICATIONS

None

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None

REFERENCE TO A MICROFICHE APPENDIX

None

BACKGROUND OF THE INVENTION

The concept of butterfly valves with a central disk is known in the art.One such butterfly valve is shown in Steele et al. U.S. Pat. No.4,836,499 and another is shown in Steele U.S. Pat. No. 5,295,659. Inboth valves a central disk pivots from a transverse or closed position,where the disk extends across a flow passage to block materials frompassing through the valve, to an axial or open position, where materialsenter one side of the valve and flow laterally alongside the disk facebefore being discharged from the opposite side of the valve. To seal thevalve the disk is positioned in the transverse position and an annularelastomer seal or sealing ring is inflated to engage an edge of the diskto form an annular seal around the periphery of the disk. To pivot thedisk to an open condition or flow through condition the elastomer sealis deflated and the disk is pivoted from the closed position to an openposition.

One of the difficulties of handling hot material with butterfly valvesis that the seals used in the butterfly valves are generally elastomerswhich have a low breakdown temperature. Often times the breakdowntemperature of the elastomer seal is below the temperature of thematerial being transported. An exposure of the elastomer seal to hightemperature materials, even if limited, can cause failure of the seal.Consequently, butterfly valve are used for handling materials that areat temperatures below the breakdown temperature of the elastomer seal toin order to avoid seal failure.

SUMMARY OF THE INVENTION

A butterfly valve for handling materials where the temperature of thematerials flowing through the butterfly valve can exceed the breakdowntemperature of the sealing member with the butterfly valve inhibitingcontact of hot transportable materials with the sealing member toisolate the hot transportable materials from the sealing member. Coolingconduits maintain at least portions of the valve that contacts thesealing member at a temperature below the breakdown temperature of thesealing member to prevent seal failure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a high temperature butterfly valve;

FIG. 2 is an exploded view of the disk of the high temperature butterflyvalve of FIG. 1;

FIG. 3 is a side view of a collar of the high temperature butterflyvalve of FIG. 1;

FIG. 4 is a sectional view of the collar of FIG. 3;

FIG. 5 is an end view of the butterfly valve;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 5;

FIG. 7 is a sectional view taken along lines 7-7 of FIG. 5;

FIG. 8 is an enlarged section view of a portion of the disk and theannular seal in a non sealing mode;

FIG. 8A is an enlarged section view of the portion of the disk of FIG. 8in the sealing mode;

FIG. 9 is an enlarged sectional view of the butterfly valve shaft; and

FIG. 10 is an isolated sectional view of the annular seal of thebutterfly valve of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is an exploded view of a high temperature butterfly valve 10 thatcan handle materials that may exceed the breakdown temperature of a sealin valve 10. Typically, butterfly valves have annular seals, which aremade from elastomers, that can expand to seal the valve and contract toallow the valve to open or close. Valve 10 includes an inlet collar 12,a housing 11, an inflatable annular seal 15, a rotateable disk 14 and anoutlet collar 13. Inlet collar 12 and outlet collar 13 typically connectto a conduit, such as a pneumatic conduit, to direct the flow ofmaterials through the butterfly valve 10. The disk 14 is pivotable abouta spindle axis 14 a to enable the disk 14 to be opened and closed. Ifdisk 14 extends transverse to the conduit, as illustrated in FIG. 1, itprevents flow of materials through the valve 10. If disk 14 is pivoted90 degrees about axis 14 a the disk 14 is an open position with the diskparallel to a central axis of collars 13 and 14 to allow material toflow through the valve 10. The components of the valve 14, with theexception of the seals, are generally made of metals to withstand theforces and the temperatures of the materials that may contact the valve.The annular seal 15, which is required to expand to seal the valve andcontract to unseal the valve, are typically made from materials such aselastomers that breakdown at a few hundred degrees. An example of anelastomer seal that expands and contract to seal and unseal a butterflyvalve is shown in Steele U.S. Pat. No. 4,836,499.

FIG. 2 is an exploded view of disk 14 of the high temperature butterflyvalve 10 of FIG. 1. Disk 14 includes a massive central disk member 20and a rim 21 that fits on the peripheral face 20 a of central diskmember 20. Located on the interior of rim 21 are three rings, an outerrib or ring 24, a central rib or ring 23 and an outer rib or ring 22. Afirst annular cooling channel 21 b is located between outer ring 24 andcentral ring 23. Similarly, an annular cooling channel 21 a is locatedbetween central ring 24 and outer ring 22. When assembled sealing ring21 is secured to central disk member 20. Spindle shaft 25 and spindleshaft 24 are secured to rim 21 and central disk member 20 allowing thedisk 14, rim 21 and shafts 24 and 25 to operate as a single unit. Forexample, when rim 21 is placed on the peripherally surface 20 a ofcentral member 20 the peripheral surface 20 a of central member 20engages the rings 22, 23 and 24 so that annular cooling channel 21 a inrim 21 and annular cooling channel 21 b in rim 21 are internally boundedby surface 20 a on disk member 20 to thereby form two side by sidecooling conduits 21 a and 21 b. While two cooling channels are shownmore or less cooling conduits may be used to cool the surface 21 d ofthe disk 14 that comes into contact with the annular seal 15. Theposition of the cooling conduits 21 a and 21 b with respect to centraldisk member 20 and annular seal 15 is shown in FIG. 8 as the centralmember 20 and rim 21 coact to form two peripherally cooling conduitswhich have an annular configuration and with an elongated cross section.The rim 21 and central member are secured to each other to maintain therim 21 in fixed position on central member 20, for example rim 21 may besecured thereto by welding or the like. Central member 20, which canfunction as a heat sink to absorb heat from materials while the coolingsystem dissipate heat a constant rate although hollow central membersmay be used in some systems.

FIG. 2 shows that disk 14 includes a first hollow shaft 25 with a hub 28extending outward from one end of central disk member 20 and a secondhollow shaft 24 having a hub 27 extending outward from an opposite endof central disk member 20 with the shafts 24 and 25 locateddiametrically opposite from each other. Shafts 24 and 25 provide a dualpurpose, first they allow one to rotate disk 14, about axis 14 a, fromthe closed position to the open position and vice versa. In addition,both shafts permit the axial flow of a cooling fluid therethrough. Whenassemble the hub 28 fits in rim 21 with conduit 25 b in fluidcommunication with passage 20 d and conduit 25 c in fluid communicationwith passage 20 c. Similarly, identical fluid passages or conduits arelocated on the opposite side of hub 28 to direct cooling fluidtherethrough (see arrows). Typically, shafts 24 and 25 may be affixed torim 21 by welding or the like. In addition the disk member 20 may alsobe affixed to rim 21 by welding to form a disk 14 of unitaryconstruction.

FIG. 2 shows the flow passages in shaft 25 allows a cooling fluid to bedelivered into the annular cooling conduits 21 b and 21 a in peripheryof disk 14, which are formed by disk surface 20 a and cooling channels21 a and 21 b. A reference to FIG. 9 shows an isolated sectional view ofthe shaft 25 located in housing 11 with a central passage 25 d thatdirects a cooling fluid, indicated by arrows through the fluid passage25 b and 25 c into the annular cooling channel 21 a and the annularcooling channel 21 b. As can be seen in FIG. 2 the fluid passages arelocated on both sides of shaft 23 so that cooling fluid can flow inopposite directions into peripheral disk cooling channels 21 a and 21 b.The fluid continues to flow through the peripheral disk cooling channels21 a and 21 b until the cooling fluid enters ports 24 a and 24 b onshaft 24 and identical ports (not shown) located on the opposite side ofshaft 24 (see FIG. 2). Consequently, in operation a cooling fluid entersshaft 25 flows into cooling channels 21 a and 21 b and then flows halfway around the disk 14 before being discharged through the fluidpassages in shaft 24. Thus a cooling fluid can be directed to the rim 21of the disk 14 to maintain the rim surface 21 d of rim 21 at atemperature that is less than the breakdown temperature of the annularseal 15. FIG. 9 shows the annular seal 15 with shaft 25 extendingtherethrough and the annular seal 15 proximate the peripheral surface 21d of rim 21. Thus, a feature of the invention is the use of a coolingconduit in the periphery of the disk 14 to maintain the peripheral edgeof the disk 14, i.e. rim 21, which contacts the annular seal 15 belowthe breakdown temperature of the annular seal 15.

A further feature of the invention is that one or multiple features maybe used to limit or inhibit the heat transfer from hot materials, whichare controlled by the butterfly valve 10, to the annular seal 15 whereinthe hot materials are at temperatures that could cause breakdown of theannular seal. By breakdown of the annular seal it is understood that theseal 15 may soften, erode or otherwise fail so that the disk 14 can notbe properly sealed to prevent passage of materials therepast.

One of the features of the invention described herein is that diskcooling may be incorporated into a butterfly valve to inhibit sealdeterioration when the materials handled by the butterfly valve exceed abreakdown temperature of the annular seal. In some cases where thetemperature of the hot materials is near or at the breakdown temperatureof the annular seal only one of the features may be used, for exampledisk cooling, and more specifically cooling of the disk parts such asthe rim that come into contact with the annular seal. In other caseswhen the temperature of the hot materials greatly exceeds the breakdowntemperature of the annular seal multiple features described herein maybe used. In still other cases one may want to use all or selectedfeatures of the invention to ensure that the annular seal is inhibitedfrom breakdown.

As hot materials that are handled by valve 10 may come into prolongedcontact with the central disk member 20 one may want to minimize heatconduction between the massive central disk member 20 and rim 21. To doso one can provide minimal surface to surface contact between rim 20 andcentral disk member 20. That is, the rings 22, 23 and 24 can be madenarrow in relation to the width of the disk 20 as illustrated in FIG. 8thus minimizing the heat sink effect of the massive central disk member20 by limiting a heat conduction path from the central disk member tothe rim 21, which are a metal, for example stainless steel. Althoughmetals are described for formation of central member 20 and rim 21 othermaterials may be used, particularly if the hot transportable materialsare corrosive to metals.

FIG. 10 shows an isolated view of the inflatable annular seal 15 takenalong lines 10-10 of FIG. 1 showing annular lobes 15 a and 15 b that canengage the housing 11 as illustrated in FIG. 8A and a shaft opening 15h. The annular seal 15 contains a curved disk sealing surface 15 chaving a radius of curvature R₂ that extends from central axis 15 e. Theradius of curvature of the sealing member surface 15 c, which ismeasured from the central axis 15 e to the outer surface 15 c, issimilar or identical to the radius of curvature R₁, (see FIG. 7 and FIG.8) of disk 14. The similar or identical radius of curvatures allows thegap D, (see FIG. 8) between the annular sealing ring 20 and theperipheral of disk 14, which allows pivoting disk 14 from the openposition to the closed position, to be minimized to thereby inhibit orprevent hot materials coming into contact with the annular seal 15 whenthe disk 14 is in the closed position as shown in FIG. 8A. By minimizingclearance D, between annular seal 15 and the disk 14 one can inhibit hotmaterials from contacting the annular seal 15 when the butterfly valveis in the closed condition since the annular seal has a limited exposureto hot materials 9 that can cause breakdown of the annular seal 15 dueto the temperatures of the hot materials exceeding the breakdowntemperature of the annular seal 15.

Thus a further feature that one may use to inhibit temperature breakdownof the annular seal 15 is to incorporate close tolerances, usually a fewthousands of an inch for example less than 0.010 inches, between theannular seal sealing surface 15 c and the disk periphery surface 21 d tolimit travel of the sealing surface 15 c and thus limit the opportunityfor the hot material to contact the annular seal 15 when in the expandedor sealed condition. FIG. 8 illustrates the close tolerance D, betweensurface 21 a and sealing surface 15 c on annular seal 15. Typically, theclearance is sufficiently large so as not to bind or hinder the openingand closing of disk 14 but sufficiently small so as to limit the ingressof hot materials into contact with the annular seal 15. Typically, inmost cases a few thousands of an inch clearance is sufficient when theradius of curvature of the disk and the seal are identical orsubstantially equal.

A further feature which may be used to inhibit heat transfer to theannular seal 15 includes having the width W₁ of disk 14 greater than thewidth W₂ of the annular seal 15 as illustrated in FIG. 8A thus limitingthe potential contact of the hot materials 9 with the annular seal 15.As a consequence the exposure of the annular seal 15 to hot materials islimited since lateral contact with the annular seal is the primary meansfor hot materials to contact annular seal 15 and hence the opportunityfor breakdown of the annular seal 15 is inhibited or prevented.

A further feature which may to used further inhibit breakdown of seal 15is sealing member cooling and housing cooling, for example FIG. 8 shows,a first cooling conduit 41 is located on a lateral annular face 15 b ofannular seal 15 and a second cooling conduit 40 is located on lateralface 15 c of annular seal 15. Conduit 40 is formed by housing 11 and anannular heat conducting flange 45. Similarly, conduit 41 is formed byhousing 11 and an annular heat conducting flange 46. While elastomersbreakdown at temperature considerably less than the temperatures whichmetals can withstand they are also poor heat conductors. Never the lessby placing cooling conduits on the opposed lateral faces 15 g and 15 hof annular seal 15 and limiting the contact area of the hot materials tothe annular seal 15 one can cool the annular seal 15 to further inhibitbreakdown of the annular seal 15 as housing 11, which supports theannular seal can also be maintained at a temperature below the breakdowntemperature of the annular seal 15.

As can be seen in FIG. 8 and FIG. 8A the heat transfer between hotmaterials in the butterfly valve 10 and the annular seal 15 may beminimized through limiting the contact area of the annular seal 15 tothe hot materials as well as through cooling valve components that comeinto contact with the annular seal 15. That is, by cooling valvecomponents that come into direct contact with the annular seal 15 totemperatures which are below the breakdown temperature of the annularseal 15 one can further enhance the ability of the butterfly valve 10 tohandle hot materials which may exceed the breakdown temperature of theannular seal.

FIG. 8A shows the annular seal 15 in the sealed condition with chamber50 pressurized thereby causing a seal surface 15 c on annular seal 15 tocontact surface 21 d on rim 21 to form a bubble tight seal therebetween.

The above features to inhibit temperature breakdown of the annular seal15 may be combined, for example by having disk 14 wider than the annularseal 15 and simultaneously cooling the disk 20 and the annular seal 15through the cooling passages located proximate thereto which can assistin maintaining the temperature of the annular seal 15 below thebreakdown temperature of the annular seal.

FIG. 3, FIG. 4, and FIG. 7 illustrates still another feature which maybe used to minimize contact of the hot transportable materials with theannular seal 15 when the disk 14 is in the open position. FIG. 3 showscollar 13 having a face plate 13 a for attachment to a conduit and aface plate 13 b for attachment to the housing 11 of butterfly valve 10.FIG. 4 is a cross section view of collar 13 showing the inlet has adiameter D₄ and the outlet a diameter D₂ with the diameter D₂ greaterthan the diameter D₄.

FIG. 5 shows an end view of butterfly valve with collar 13 openinghaving a diameter D₄ and a disk 14 located therein. As can be seen inFIG. 5 hot transportable materials can flow on both sides of disk 14 ina straight flow path since the annular seal 15 is radially offset andtherefore impingement with annular seal 15 is inhibited.

FIG. 7 shows a cross section view of collar 13 and collar 14 attached tohousing 11. Collar 13 which has an inlet diameter D₄, which mates withthe diameter of a conduit that delivers hot materials to butterfly valve10, has an outlet diameter D₂ which is larger than inlet diameter D₄.The internal diameter of collar 13 expands to a diameter D₂ at the disk14 and reduces to a diameter D₄ at the second collar 14 to also matewith the conduit that receives the hot materials from the butterflyvalve 10. The annular seal 15 has a diameter D₃ which is greater thanD₂. Thus the annular seal 15 is radially offset from a straight lineflow path through the valve 10 to further inhibit hot transportablematerials from contacting the annular seal 15 as materials flows throughthe butterfly valve 10. That is, when the disk 14 is in the opencondition the hot materials, which generally contain mass and sufficientmomentum to inhibit radial outflow toward the elastomer seal 15 thusfurther inhibit direct contact and heat transfer from the hot materialsto the annular seal 15.

It should be pointed out that while an annular seal 15 has beendescribed herein other shapes of seals may be used with the shut off thevalve to inhibit and prevent breakdown of the seal if the material beinghandle has a temperature that is above the breakdown temperature of theseal.

The invention further includes a method of intermittent delivery of hotconduit transportable materials though a valve 14 that includes portionsof the valve that have a breakdown temperature that is less than thetemperature of the transportable materials comprising the steps of:pivoting a disk 14 to a closed condition; expanding an expandable seal15 until the expandable seal contacts only a portion of a rim 20 of thedisk; directing a cooling fluid through at least one cooling conduit 21a, 21 b in the rim 20 of the disk 14 to maintain the temperature of theportion of the rim that contacts the expandable seal 15 at a temperaturethat is below a breakdown temperature of the expandable seal. One canalso including a step of directing a cooling fluid through a housingsupporting the expandable seal. One can contract the expandable seal 15and pivot the disk 14 to an open condition. Once in the open conditionthe method can include the step of directing a transportable materialthrough housing 11 with the transportable material having sufficientmomentum so as to inhibit or prevent bringing the transportable materialfrom coming into contact with the expandable seal 15. The cooling fluidmay be directed into a first shaft 25 and out a second shaft 24 with thefirst and second shaft located diametrically opposite from each other.

1. A butterfly valve for opening and closing a passage therethroughcomprising; a housing; an annular seal mounted in said housing, saidannular seal radially expandable; and a disk pivotally mounted in saidhousing with said disk having a width greater than a width of saidannular seal so that's when the disk is in the closed condition thewidth of the disk isolates the annular seal from transportable materialsthat may be at a temperature that exceeds the breakdown temperature ofthe annular seal.
 2. The butterfly valve of claim 1 wherein the annularseal has a sealing face with a first radius of curvature and the diskhas a sealing face with a similar radius of curvature so as to minimizethe clearance between the disk and the sealing member when the disk isrotated from a closed position to an open position or vice versa and theannular seal is in an uninflected condition.
 3. The butterfly valve ofclaim 1 including a peripheral cooling conduit located in said disk tocool a peripheral surface of the disk, which can contact the annularseal, to a temperature below the breakdown temperature of the annularseal.
 4. The butterfly valve of claim 1 including a set of collars eachhaving a conduit connecting end having a diameter less than the diameterof the annular seal to inhibit hot materials from contacting the annularseal as hot material flows through the butterfly valve.
 5. The butterflyvalve of claim 1 including a first annular heat conducting flangeproximate a first side of the annual seal and a second annular heatconducting flange proximate an opposite side of the annular seal todirect cool the annular seal so as to inhibit the temperature of theannular seal exceeding the breakdown temperature of the annular seal. 6.The butterfly valve of claim 1 including a shaft on the disk with shafthaving a conduit therein wherein a cooling fluid may be directed axiallythrough the shaft on the disk.
 7. The butterfly valve of claim 3 whereincooling conduits in the disk comprises annular conduits having an inletand an outlet with the inlet and the outlet diametrical opposite fromeach other.
 8. A butterfly valve for opening and closing a passagecomprising; a housing; an expandable seal mounted in said housing; and acentral member pivotally mounted in said housing with said centralmember having a width greater than a width of said expandable seal sothat when the central member is in a closed condition the width of thecentral member substantially isolates the seal from contacting thetransportable materials that may be at a temperature that exceeds thebreakdown temperature of the expandable seal.
 9. The butterfly valve ofclaim 8 wherein the expandable seal is an elastomer having a sealingsurface with a radius of curvature substantially equal to a radius ofcurvature of a portion of the central member that can engage theexpandable seal to block passage therebetween.
 10. The butterfly valveof claim 9 wherein the central member includes a peripheral coolingchannel for maintaining the temperature of a portion of the centralmember that contacts the expandable seal when the central member is in aclosed condition.
 11. The butterfly valve of claim 10 including ahousing supporting the expandable seal with at least one cooling channelextending alongside the expandable seal to assist in mating theexpandable seal and the housing at a temperature below the breakdowntemperature of the expandable seal.
 12. The butterfly valve of claim 11wherein the butterfly valve includes an inlet collar and an outletcollar with each of the collars having a conduit attachment faceplatewith a diameter less than an internal diameter of the expandable seal toinhibit hot transportable materials flowing through the butterfly valvefrom contacting the expandable seal.
 13. The butterfly valve of claim 12wherein a clearance between the central member and the expandable seal,when the expandable seal is in an unexpanded condition is less than0.010 inches.
 14. The butterfly valve of claim 13 wherein the centralmember is massive and a rim secured thereto includes ribs for engagingonly a portion of the central member to inhibit heat conduction betweenthe central member and the rim.
 15. The butterfly valve of claim 14wherein the housing and the central member are metal and the expandableseal comprise an elastomer.
 16. The method of intermittent delivery ofconduit transportable materials through a valve that includes portionsthat have a breakdown temperature that is less than the temperature ofthe transportable materials comprising the steps of: pivoting a disk toa closed condition; expanding an expandable seal until the expandableseal contacts only a portion of a rim of the disk; directing a coolingfluid through at least one cooling conduit in the rim of the disk tomaintain the temperature of the portion of the rim that contacts theexpandable seal at a temperature that is below a breakdown temperatureof the expandable seal.
 17. The method of claim 16 including the step ofdirecting a cooling fluid through a housing supporting the expandableseal.
 18. The method of claim 17 including the step of contracting theexpandable seal and pivoting the disk to an open condition whiledirecting cooling fluid through the disk.
 19. The method of claim 18including the step of directing a transportable material through thehousing with sufficient momentum so as to inhibit or prevent bringingthe transportable material into contact with the expandable seal. 20.The method of claim 19 including the step of directing a cooling fluidinto a first shaft and out a second shaft with the first and secondshafts located diametrically opposite from each other.